JP4803115B2 - Single-phase DC brushless motor drive device - Google Patents

Description

  The present invention relates to a drive device for a single-phase DC brushless motor, and more particularly to a drive device for a single-phase DC brushless motor that can improve the efficiency of the single-phase DC brushless motor with a simple circuit configuration.

As a conventional single-phase DC brushless motor driving device, a dedicated motor driving IC, a microcomputer or the like is generally used, and a FET or transistor, for example, is used as a switching element to detect the magnetic pole position of the rotor. For example, a Hall element is used. In response to the position detection signal from the sensor, an output command is issued from the distribution circuit in the motor drive IC to the switching element. If the brushless motor to be driven is a single-phase full-wave DC brushless motor, an H-bridge is configured. A single-phase DC brushless motor is driven by causing a bidirectional current to flow through the motor coil by alternately driving the switching elements located diagonally among the four switching elements. As an example of such a single-phase DC brushless motor drive device, for example, there is a “motor drive circuit” disclosed in JP-A-9-331692.
Japanese Patent Laid-Open No. 9-331692

  However, in the conventional single-phase DC brushless motor driving device described above, the efficiency of the single-phase DC brushless motor is poor because the magnet is energized even at the magnetic pole position where torque is not generated, the heat generation of the motor coil and the control board, There was a situation that caused an increase in power consumption.

  The present invention has been made in view of the above-described conventional circumstances, and controls the energization of the motor coil based on the detection of the magnetic pole position, so that the efficiency of the single-phase DC brushless motor can be improved with a simple circuit configuration. It aims at providing the drive device of a phase DC brushless motor.

In order to achieve the above object, a driving device for a single-phase DC brushless motor according to the present invention includes a magnet rotor having a plurality of magnetic poles and rotatably supported, a stator core disposed to face the magnet rotor, A single-phase DC brushless motor driving device for driving a single-phase DC brushless motor having a motor coil held by the stator core, the magnetic pole position detection sensor for detecting the magnetic pole position of the magnet rotor, and the motor coil And a control means for turning on or off the switching element to energize or de-energize the motor coil based on a magnetic pole position detection signal output from the magnetic pole position detection sensor. And the control means includes a surface magnet of the magnet rotor facing the stator core. When the absolute value of the density variation rate is within a predetermined range, which performs energization control that does not energized the motor coil, the current control, the central axis and the center of the stator core of the S pole of the magnet rotor Is less than a predetermined angle and when the center of the N pole of the magnet rotor and the center axis of the stator core are less than a predetermined angle, the motor coil is deenergized and the center of the S pole of the magnet rotor is When the center axis of the stator core is not less than a predetermined angle and when the center of the N pole of the magnet rotor and the center axis of the stator core are not less than a predetermined angle, the motor coil is energized, The angle is such that the absolute value of the gradient of the surface magnetic flux density of the magnet rotor is an angle at which the surface magnetic flux maximum value × SIN (45 deg) or less . Features.

  In the driving device for a single-phase DC brushless motor according to the present invention, the magnetic pole position detection sensor includes an on-magnetic pole position detection sensor that detects a magnetic pole position at which energization of the motor coil is started, and stops energization of the motor coil. A second feature is that it includes an off-magnetic pole position detection sensor that detects a magnetic pole position to be detected.

  In the driving device for a single-phase DC brushless motor according to the present invention, the control means may be configured such that the control means outputs a magnetic pole output from the off-magnetic pole position detection sensor until a predetermined time has elapsed since the start of the single-phase DC brushless motor. A third feature is that the switching element is turned on or off based on a position detection signal.

  In the driving device for a single-phase DC brushless motor according to the present invention, the control means may perform the switching based on a magnetic pole position detection signal output from the off-magnetic pole position detection sensor when the single-phase DC brushless motor is locked. The fourth feature is that the element is controlled to be turned on or off.

  Furthermore, in the driving device for a single-phase DC brushless motor according to the present invention, the control means controls the switching element to be turned on or off after a predetermined time has elapsed after the magnetic pole position detection signal is output from the magnetic pole position detection sensor. This is the fifth feature.

  In the drive device for the single-phase DC brushless motor according to the first aspect of the present invention, when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor facing the stator core is within a predetermined range, the motor coil is not energized. Thus, the magnet rotor is not energized at the magnetic pole position where torque is not generated, and the efficiency of the single-phase DC brushless motor can be improved. It is possible to avoid a situation such as an increase in electric power, and as a result, it is possible to realize a driving device for a single-phase DC brushless motor that can improve the efficiency of the single-phase DC brushless motor with a simple circuit configuration.

  In the driving device for a single-phase DC brushless motor according to the second aspect of the present invention, an on-pole position detection sensor for detecting a magnetic pole position at which energization of the motor coil is started, and a magnetic pole position at which energization of the motor coil is stopped are provided. Since the configuration includes the off-magnetic pole position detection sensor for detection, the efficiency of the single-phase DC brushless motor can be increased regardless of the rotational speed of the single-phase DC brushless motor.

  In the driving device for the single-phase DC brushless motor according to the third aspect of the present invention, the control means outputs the signal from the off-pole position detection sensor until a predetermined time has elapsed since the start of the single-phase DC brushless motor. Based on the magnetic pole position detection signal, the switching element is turned on or off, and the motor coil is energized or deenergized for a predetermined period of time, so it is reliable and stable regardless of the magnetic rotor magnetic pole position when the motor is started. Thus, the single-phase DC brushless motor can be started.

  In the drive device for the single-phase DC brushless motor according to the fourth feature of the present invention, the control means outputs the signal from the off-pole position detection sensor until a predetermined time has elapsed since the start of the single-phase DC brushless motor. Based on the magnetic pole position detection signal, the switching element is controlled to be turned on or off, and the motor coil is controlled to be energized or de-energized. A phase DC brushless motor can be activated.

  In the drive device for the single-phase DC brushless motor according to the fifth aspect of the present invention, the control device turns the switching element on or off after a predetermined time has elapsed after the magnetic pole position detection signal is output from the magnetic pole position detection sensor. Since it controls, the drive device of the single phase DC brushless motor which can improve the efficiency of the single phase DC brushless motor at a desired number of rotations can be realized.

  Embodiments of a single-phase DC brushless motor driving apparatus according to the present invention will be described below in detail in the order of [Embodiment 1] and [Embodiment 2] with reference to the drawings.

[Example 1]
FIG. 1 is a configuration diagram of a driving device for a single-phase DC brushless motor according to a first embodiment of the present invention, and FIG. 2 is a diagram for explaining a temporal transition of relative positional relationships of main components in the single-phase DC brushless motor. FIG.

  1 and 2, the single-phase DC brushless motor to be driven by the driving device of the single-phase DC brushless motor of the present embodiment has a plurality of magnetic poles, and the magnet surface is rotatable to face the stator cores 9a and 9b. A supported magnet rotor 10; stator cores 9a and 9b disposed opposite to the magnet rotor 10; and a motor coil 5 that is supported by the stator cores 9a and 9b and wound in a reverse direction. It is a configuration.

  In FIG. 1, the driving device for the single-phase DC brushless motor of this embodiment includes magnetic pole position detection sensors 6 a and 6 b that detect the magnetic pole position of the magnet rotor 10, and switching elements 3 a and 3 b connected to the motor coil 5. , 4a and 4b, a control circuit 7, a startup time instruction circuit 41, and a lock detection circuit 42.

  For example, a Hall IC is used for the magnetic pole position detection sensors 6a and 6b, and an on-magnetic pole position detection sensor 6a for detecting a magnetic pole position at which energization of the motor coil 5 is started and a magnetic pole position at which the motor coil 5 is de-energized are detected. Off-magnetic pole position detection sensor 6b. The on-pole position detection sensor 6a and the off-pole position detection sensor 6b are attached within the magnetic field range near the magnet rotor 10, and notify the control circuit 7 of the position of the magnetic pole of the magnet rotor 10 by a magnetic pole position detection signal.

  The H bridge circuit includes p-channel FETs 3a and 3b as switching elements 3a, 3b, 4a and 4b, n-channel FETs 4a and 4b, and resistors R1 to R4.

  The source terminals of the p-channel FETs 3a and 3b are connected to the motor driving power source (positive potential) 1, the drain terminal of the p-channel FET 3a is connected to the drain terminal of the n-channel FET 4a, and the drain of the p-channel FET 3b. The drain terminal of the n-channel FET 4b is connected to the terminal, and the source terminals of the n-channel FETs 4a and 4b are connected to the motor driving power source (negative potential) 2. The gate terminal of the p-channel FET 3a is connected to the motor driving power source (positive potential) 1 through the resistor R1, and is also connected to the drain terminal of the n-channel FET 4b. The gate terminal of the p-channel FET 3b is also connected to the motor driving power source (positive potential) 1 through the resistor R2, and is also connected to the drain terminal of the n-channel FET 4a.

  Further, in the H bridge circuit having such a connection relationship, the motor coil 5 is connected between the connection point of the p-channel FET 3a and the n-channel FET 4a and the connection point of the p-channel FET 3b and the n-channel FET 4b. ing.

  The control circuit 7 also switches the switching elements 3a, 3b, 4a and 4b of the H bridge circuit based on the magnetic pole position detection signals output from the magnetic pole position detection sensors (the on-pole position detection sensor 6a and the off-pole position detection sensor 6b). Is turned on or off so that the motor coil 5 is energized or de-energized. Specifically, the control signals output from the control circuit 7 are connected to the gate terminals of the n-channel FETs 4a and 4b, respectively, and the control signals are connected to the control power supply 8 via the resistors R3 and R4, respectively. In particular, the motor coil 5 is not energized when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 10 facing the stator cores 9a, 9b is within a predetermined range.

  The start time instruction circuit 41 is realized by a CR circuit having a time constant determined by a capacitor and a resistor, a timer IC, or the like, and controls whether a predetermined time has elapsed since the start of the single-phase DC brushless motor. 7 is notified.

  The control circuit 7 refers to the output from the start time instruction circuit 41, and detects the magnetic pole position output from the off magnetic pole position detection sensor 6b until a predetermined time has elapsed since the start of the single-phase DC brushless motor. Based on the signal, the switching elements 3a, 3b, 4a and 4b are turned on or off.

  Furthermore, the lock detection circuit 42 detects whether or not the single-phase DC brushless motor is in a locked state and notifies the control circuit 7. The lock detection circuit 42 detects the magnetic poles from the on-pole position detection sensor 6 a and the off-pole position detection sensor 6 b. A configuration that detects that there is no on / off output switching by referring to the position detection signal by an AC coupling circuit using a transistor and a capacitor, a configuration that directly detects that there is no change in the rotational speed by a microcomputer, or a lock state The overcurrent is detected by a shunt resistor or the like.

  The control circuit 7 refers to the output from the lock detection circuit 42 and switches the switching elements 3a and 3b based on the magnetic pole position detection signal output from the off-magnetic pole position detection sensor 6b when the single-phase DC brushless motor is locked. , 4a and 4b are turned on or off.

  Next, the operation of the driving device for the single-phase DC brushless motor of the present embodiment having the above-described configuration will be described in detail with reference to FIG. 2, FIG. 3, and FIG. Here, FIG. 3 is a time chart for explaining the relationship between the magnetic core surface magnetic flux density of the single-phase DC brushless motor and the energization timing, and FIG. 4 is detected by the on-pole position detection sensor 6a and the off-pole position detection sensor 6b. It is explanatory drawing explaining the electricity supply state of a magnetic pole position and a motor coil.

  First, with reference to FIG. 2, energization / non-energization control of the motor coil 5 performed by the control circuit 7 in accordance with the change in the magnetic pole position of the magnet rotor 10 will be described. Here, FIG. 2 shows the relative positional relationship among the motor coil 5, the stator cores 9a and 9b, the magnet rotor 10, the on-pole position detection sensor 6a, and the off-pole position detection sensor 6b in the single-phase DC brushless motor, and step S1. ~ Step S6 illustrates the temporal transition of the magnetic pole position of the magnet rotor 10 (transition from step S1 to step S6 with the passage of time).

  First, in step S1, when the center of the N pole of the magnet rotor 10 passes a center angle of the stator core 9a by a predetermined angle (α °), the on-pole position detection sensor 6a switches the magnetic pole of the magnet rotor 10 (N pole). To S pole). At this time, the off magnetic pole position detection sensor 6b detects the south pole of the magnet rotor 10.

  The control circuit 7 receives the magnetic pole position detection signals from the on magnetic pole position detection sensor 6a and the off magnetic pole position detection sensor 6b, and activates the control signal to the gate terminal of the n channel FET 4b to turn on the n channel FET 4b. In addition, the control signal to the gate terminal of the n-channel FET 4a is made inactive to turn off the n-channel FET 4a. By turning on the n-channel FET 4b, the gate terminal of the p-channel FET 3a is connected to the motor driving power source (negative potential) 2, so that the p-channel FET 3a is also turned on, and the motor coil 5 is in the energized state. (See FIG. 4; step S1). At this time, the stator core 9 a is magnetized to the N pole, and the stator core 9 b is magnetized to the S pole, and gives a rotational torque to the magnet rotor 10.

  Next, in step S2, since the magnetic poles of the magnet rotor 10 detected by the on-magnetic pole position detection sensor 6a and the off-magnetic pole position detection sensor 6b have not changed (same as the S pole), the energization state of the motor coil 5 is step S1. (See FIG. 4; step S2).

  Next, in step S3, when the angle between the center of the S pole of the magnet rotor 10 and the center axis of the stator core 9a becomes a predetermined angle (β °), the off-pole position detection sensor 6b detects the magnetic pole of the magnet rotor 10. Is detected (from S pole to N pole). At this time, the on-pole position detection sensor 6 a detects the south pole of the magnet rotor 10.

  The control circuit 7 receives the magnetic pole position detection signals from the on magnetic pole position detection sensor 6a and the off magnetic pole position detection sensor 6b, and sets the control signals to the gate terminals of the n-channel FETs 4a and 4b to be inactive. The FETs 4a and 4b are turned off. By turning off the n-channel FET 4b, the gate terminal of the p-channel FET 3a is connected to the motor driving power source (positive potential) 1 via the resistor R1, and the p-channel FET 3a is also turned off, The coil 5 is in a non-energized state (see FIG. 4; step S3).

  Next, in step S4, when the center of the S pole of the magnet rotor 10 passes the center axis of the stator core 9a by a predetermined angle (α °), the on-pole position detection sensor 6a switches the magnetic pole of the magnet rotor 10 (S From the pole to the N pole). At this time, the off magnetic pole position detection sensor 6b detects the N pole of the magnet rotor 10.

  The control circuit 7 receives the magnetic pole position detection signals from the on magnetic pole position detection sensor 6a and the off magnetic pole position detection sensor 6b, and activates the control signal to the gate terminal of the n channel FET 4a to turn on the n channel FET 4a. In addition, the control signal to the gate terminal of the n-channel FET 4b is made inactive to turn off the n-channel FET 4b. By turning on the n-channel FET 4a, the gate terminal of the p-channel FET 3b is connected to the motor driving power source (negative potential) 2, so that the p-channel FET 3b is also turned on. In this case, the energization state is in the opposite direction (see FIG. 4; step S4). At this time, the stator core 9 a is magnetized to the S pole, and the stator core 9 b is magnetized to the N pole, and gives a torque to the magnet rotor 10.

  Next, in step S5, since the magnetic poles of the magnet rotor 10 detected by the on-pole position detection sensor 6a and the off-pole position detection sensor 6b have not changed (keep N pole), the reverse energization state of the motor coil 5 is It is maintained similarly to step S4 (see FIG. 4; step S5).

  Next, in step S6, when the angle between the center of the N pole of the magnet rotor 10 and the center axis of the stator core 9a becomes a predetermined angle (β °), the off-pole position detection sensor 6b detects the magnetic pole of the magnet rotor 10. Is detected (from N pole to S pole). At this time, the on-pole position detection sensor 6 a detects the N pole of the magnet rotor 10.

  The control circuit 7 receives the magnetic pole position detection signals from the on magnetic pole position detection sensor 6a and the off magnetic pole position detection sensor 6b, and sets the control signals to the gate terminals of the n-channel FETs 4a and 4b to be inactive. The FETs 4a and 4b are turned off. By turning off the n-channel FET 4a, the gate terminal of the p-channel FET 3b is connected to the motor driving power source (positive potential) 1 via the resistor R2, so that the p-channel FET 3b is also turned off. The coil 5 is in a non-energized state (see FIG. 4; step S6).

  Thereafter, the operations from step S1 to step S6 are repeated.

  In Step S1, Step S3, Step S4 and Step S6, when the predetermined angles (α °) and (β °) are equal to or smaller than the predetermined values, that is, the surface of the magnet rotor 10 facing the central axis of the stator cores 9a and 9b. Even when the motor coil 5 is energized when the magnetic flux density is close to the peak value, the repulsive force acting between the magnet rotor 10 and the stator cores 9a and 9b works toward the center of the rotation axis of the motor. It is not output as torque.

  Further, since the amount of change in the magnetic flux of the magnet rotor 10 crossing the front of the stator cores 9a and 9b is small, the voltage induced in the motor coil 5 is also small, and the apparent voltage value applied to the motor coil 5 is large. A large current flows through the motor coil 5. Since this current does not contribute to the motor torque, all of it is wasted electric power, causing the efficiency of the single-phase DC brushless motor to be reduced.

  In the driving device for the single-phase DC brushless motor of the present embodiment, as shown in FIG. 3, in steps S1, S3, S4, and S6, predetermined angles (α °) and (β °) are provided and the motor is provided. The efficiency of the single-phase DC brushless motor is increased by controlling the energization / non-energization state of the coil 5.

  Here, the predetermined angles (α °) and (β °) are angles at which the absolute value of the gradient of the surface magnetic flux density of the magnet rotor 10 is equal to or less than “surface magnetic flux maximum value × SIN (45 deg)”. In the case of a single-phase DC brushless motor of (M is a positive integer), it is “45 / (M / 2) deg” or less. More preferably, the angle is such that “surface magnetic flux maximum value × SIN (15 deg) <inclination absolute value <surface magnetic flux maximum value × SIN (36 deg)”, and if it is an M pole single-phase DC brushless motor, “15 / (M / 2) deg <α, βdeg <36 / (M / 2) deg ”or less.

  Further, when the motor is started, if the vicinity of the peak value of the surface magnetic flux density of the magnet rotor 10 is located near the central axis of the stator cores 9a and 9b, only the magnetic pole position detection signal output from the off-magnetic pole position detection sensor 6b is used. On the basis of this, the switching elements 3a, 3b, 4a and 4b are controlled to be turned on or off, and the control to put the motor coil 5 in the energized / deenergized state is performed for a predetermined time, so that the single-phase DC brushless motor can be started stably. Here, the predetermined time is instructed to the control circuit 7 by the activation time instruction circuit 41, and the predetermined time is a time during which stable driving is ensured with respect to the load of each single-phase DC brushless motor.

  Further, when the motor is locked, the switching elements 3a, 3b, 4a and 4b are turned on or off based on only the magnetic pole position detection signal output from the off magnetic pole position detection sensor 6b, and the motor coil 5 is energized / de-energized. By performing the control as described above for a predetermined time, the single-phase DC brushless motor can be stably started regardless of the relative position relationship between the peak value of the surface magnetic flux density of the magnet rotor 10 and the central axis of the stator cores 9a and 9b. The motor lock is detected by the lock detection circuit 42. When the motor lock is detected, the control circuit 7 performs energization / non-energization control of the motor coil 5 based only on the magnetic pole position detection signal output from the off magnetic pole position detection sensor 6b. After the motor lock is released, energization / non-energization control of the motor coil 5 is performed based on the magnetic pole position detection signals output from the off magnetic pole position detection sensors 6a and 6b.

  As described above, in the driving device for the single-phase DC brushless motor according to the present embodiment, the magnet rotor 10 having a plurality of magnetic poles and rotatably supported, and the stator cores 9a and 9b disposed facing the magnet rotor 10 are provided. A single-phase DC brushless motor that drives a single-phase DC brushless motor having a motor coil 5 held by the stator cores 9a and 9b, and a magnetic pole position detection sensor that detects the magnetic pole position of the magnet rotor 10 6a, 6b, switching elements 3a, 3b, 4a and 4b connected to motor coil 5, and switching elements 3a, 3b, 4a and 4b based on magnetic pole position detection signals output from magnetic pole position detection sensors 6a and 6b. A control circuit 7 for turning on or off the motor coil 5 to energize or de-energize the motor coil 5; A, the control circuit 7, when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 10 to the stator core 9a, 9b and the counter is within a predetermined range, and the motor coil 5 to prevent an energized state. The magnetic pole position detection sensor includes an on magnetic pole position detection sensor 6a that detects a magnetic pole position at which energization of the motor coil 5 is started, an off magnetic pole position detection sensor 6b that detects a magnetic pole position at which the motor coil 5 is de-energized, It is set as the structure provided with.

  As described above, when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 10 facing the stator cores 9a, 9b is within a predetermined range, the motor coil 5 is controlled so as not to be energized. It is possible to improve the efficiency of the single-phase DC brushless motor and avoid the situation of heat generation of the motor coil 5 and the control board or increase of power consumption as in the past. As a result, a single-phase DC brushless motor driving apparatus that can improve the efficiency of the single-phase DC brushless motor with a simple circuit configuration can be realized.

  In the driving device for the single-phase DC brushless motor of this embodiment, the control circuit 7 causes the magnetic pole position output from the off-magnetic pole position detection sensor 6b until a predetermined time elapses after the single-phase DC brushless motor is started. Based on the detection signal, the switching elements 3a, 3b, 4a and 4b are controlled to be turned on / off and the motor coil 5 is controlled to be energized / de-energized for a predetermined time. Regardless of this, the single-phase DC brushless motor can be started reliably and stably.

  Further, in the driving device for the single-phase DC brushless motor of this embodiment, the switching element 3a is controlled by the control circuit 7 when the single-phase DC brushless motor is locked based on the magnetic pole position detection signal output from the off-magnetic pole position detection sensor 6b. , 3b, 4a and 4b are controlled to turn on / off the motor coil 5 so that the motor coil 5 is energized / de-energized, so that the single-phase DC is reliably and stably applied regardless of the magnetic pole position of the magnet rotor 10 when the motor is locked. The brushless motor can be activated.

[Example 2]
Next, FIG. 5 is a configuration diagram of a driving device for a single-phase DC brushless motor according to Embodiment 2 of the present invention, and FIG. 6 shows a temporal transition of relative positional relationships of main components in the single-phase DC brushless motor. It is explanatory drawing demonstrated.

  5 and 6, the single-phase DC brushless motor to be driven by the single-phase DC brushless motor driving apparatus of the present embodiment has a plurality of magnetic poles, and the magnet surface is rotatable facing the stator cores 19 a and 19 b. A magnet rotor 20 that is supported; stator cores 19a and 19b disposed opposite to the magnet rotor 20; and a motor coil 15 that is held by the stator cores 19a and 19b and wound in a reverse direction. It is a configuration.

  In FIG. 5, the driving device for the single-phase DC brushless motor of this embodiment includes a magnetic pole position detection sensor 16 b that detects the magnetic pole position of the magnet rotor 20, and switching elements 13 a, 13 b, and 14 a connected to the motor coil 15. And an H bridge circuit having 14b and a control circuit 17.

  The magnetic pole position detection sensor 16b is an off magnetic pole position detection sensor 16b that uses, for example, a Hall IC and detects a magnetic pole position at which the motor coil 5 is de-energized. The off magnetic pole position detection sensor 16b is attached within the magnetic field range near the magnet rotor 20, and notifies the control circuit 17 of the magnetic pole position of the magnet rotor 20 by a magnetic pole position detection signal. Note that one of the features different from the first embodiment of the present embodiment is that the magnetic pole position detection sensor does not include an on-pole position detection sensor.

  The H bridge circuit includes p-channel FETs 13a and 13b as switching elements 13a, 13b, 14a and 14b, n-channel FETs 14a and 14b, resistors R11 to R14, and capacitors C11 and C12.

  The source terminals of the p-channel FETs 13a and 13b are respectively connected to the motor driving power source (positive potential) 11, the drain terminal of the p-channel FET 13a is connected to the drain terminal of the n-channel FET 14a, and the drain of the p-channel FET 13b. The drain terminal of the n-channel FET 14b is connected to the terminal, and the source terminals of the n-channel FETs 14a and 14b are connected to the motor driving power source (negative potential) 12. The gate terminal of the p-channel FET 13a is connected to the motor driving power source (positive potential) 11 through the resistor R11, and is also connected to the drain terminal of the n-channel FET 14b. The gate terminal of the p-channel FET 13b is also connected to the motor driving power source (positive potential) 11 through the resistor R12, and is also connected to the drain terminal of the n-channel FET 14a.

  Note that one of the features different from the first embodiment of the present embodiment is that the gate terminals of the n-channel FETs 14a and 14b are connected to the motor driving power source (negative potential) 12 via the capacitors C11 and C12, respectively. It is.

  Further, in the H bridge circuit having such a connection relationship, the motor coil 15 is connected between the connection point of the p-channel FET 13a and the n-channel FET 14a and the connection point of the p-channel FET 13b and the n-channel FET 14b. ing.

  In addition, the control circuit 17 controls the switching elements 13a, 13b, 14a and 14b of the H bridge circuit to be turned on or off based on the magnetic pole position detection signal output from the off magnetic pole position detection sensor 16b, and energizes the motor coil 15. Turn off the power. Specifically, the control signals output from the control circuit 17 are connected to the gate terminals of the n-channel FETs 14a and 14b, respectively, and the control signals are connected to the control power supply 18 via the resistors R13 and R14, respectively.

  In this way, each control signal is connected to the resistor R14 and the capacitor C11, and the resistor R13 and the capacitor C12. When the control signal is activated, the control signal (the gate terminals of the n-channel FETs 14a and 14b) is connected. The potential increases with a delay time (γsec) determined by the time constant of the resistor R14 and the capacitor C11 or the resistor R13 and the capacitor C12, respectively. In particular, the motor coil 15 is not energized when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 20 facing the stator cores 19a, 19b is within a predetermined range.

  Next, the operation of the driving device for the single-phase DC brushless motor of the present embodiment having the above-described configuration will be described in detail with reference to FIGS. 6, 7 and 8. FIG. Here, FIG. 7 is a time chart for explaining the relationship between the magnetic core surface magnetic flux density of the single-phase DC brushless motor and the energization timing. FIG. 8 shows the magnetic pole position detected by the off magnetic pole position detection sensor 16b and the motor coil 15. It is explanatory drawing explaining an electricity supply state.

  First, with reference to FIG. 6, the energization / non-energization control of the motor coil 15 performed by the control circuit 17 in accordance with the change in the magnetic pole position of the magnet rotor 20 will be described. Here, FIG. 6 shows the relative positional relationship among the motor coil 15, the stator cores 19a and 19b, the magnet rotor 20, and the off-pole position detection sensor 16b in the single-phase DC brushless motor, and the magnet rotor 20 is shown in steps S11 to S17. This illustrates a temporal transition of the magnetic pole position (transition from step S11 to step S17 with the passage of time).

  First, in step S11, when the angle between the center of the N pole of the magnet rotor 20 and the center axis of the stator core 19a becomes a predetermined angle (β °), the off-pole position detection sensor 16b detects the magnetic poles of the magnet rotor 20. Switching (from N pole to S pole) is detected.

  In response to the magnetic pole position detection signal from the off magnetic pole position detection sensor 16b, the control circuit 17 sets the control signal to the gate terminal of the n-channel FET 14a to be inactive and controls the n-channel FET 14a to turn off. The control signal to the gate terminal of the type FET 14b is activated to turn on the n-channel type FET 14b. At this time, the gate terminal of the n-channel FET 14b rises with a delay time (γsec) determined by the time constant of the resistor R13 and the capacitor C12.

  Next, in step S12, when the center of the N pole of the magnet rotor 20 passes a predetermined angle (α °) through the central axis of the stator core 19a, the n-channel FET 14b is turned on, and the gate terminal of the p-channel FET 13a is turned on. Is connected to the motor driving power source (negative potential) 12, the p-channel FET 13a is also turned on, and the motor coil 15 is energized (see FIG. 8; step S12). At this time, the stator core 19 a is magnetized to the N pole, and the stator core 19 b is magnetized to the S pole, and gives a rotational torque to the magnet rotor 20.

  Next, in step S13, since the magnetic pole of the magnet rotor 20 detected by the off-magnetic pole position detection sensor 16b has not changed (same as the S pole), the energized state of the motor coil 15 is maintained as in step S12 ( FIG. 4; see step S13).

  Next, in step S14, when the angle between the center of the S pole of the magnet rotor 20 and the center axis of the stator core 19a becomes a predetermined angle (β °), the off-pole position detection sensor 16b detects the magnetic pole of the magnet rotor 20. Is detected (from S pole to N pole).

  In response to the magnetic pole position detection signal from the off magnetic pole position detection sensor 16b, the control circuit 17 makes the control signal to the gate terminal of the n-channel FET 14b inactive and controls the n-channel FET 14b off. By turning off the n-channel FET 14b, the gate terminal of the p-channel FET 13a is connected to the motor driving power source (positive potential) 11 via the resistor R11, so that the p-channel FET 13a is also turned off. The coil 15 is in a non-energized state (see FIG. 8; step S14). At this time, the control signal to the gate terminal of the n-channel FET 14a is activated to turn on the n-channel FET 14a. At this time, the gate terminal of the n-channel FET 14a rises with a delay time (γsec) determined by the time constant of the resistor R14 and the capacitor C11.

  Next, in step S15, when the center of the south pole of the magnet rotor 20 has passed the central axis of the stator core 19a by a predetermined angle (α °), the n-channel FET 14a is turned on, and the gate terminal of the p-channel FET 13b. Is connected to the motor driving power source (negative potential) 12, the p-channel FET 13b is also turned on, and the motor coil 15 is energized in the reverse direction (see FIG. 8; step S15). At this time, the stator core 19a is magnetized to the S pole, and the stator core 19b is magnetized to the N pole, and a rotational torque is applied to the magnet rotor 20.

  Next, in step S16, since the magnetic pole of the magnet rotor 20 detected by the off magnetic pole position detection sensor 6b has not changed (still remains N pole), the reverse energization state of the motor coil 15 is maintained in the same manner as in step S15. (See FIG. 8; step S16).

  Next, in step S17, as in step S11, when the angle between the center of the N pole of the magnet rotor 20 and the center axis of the stator core 19a becomes a predetermined angle (β °), the off-pole position detection sensor 16b. Detects the switching of the magnetic poles of the magnet rotor 20 (from N pole to S pole).

  In response to the magnetic pole position detection signal from the off magnetic pole position detection sensor 16b, the control circuit 17 makes the control signal to the gate terminal of the n-channel FET 14a inactive and controls the n-channel FET 14a off. By turning off the n-channel FET 14a, the gate terminal of the p-channel FET 13b is connected to the motor driving power source (positive potential) 11 via the resistor R12, so that the p-channel FET 13b is also turned off. The coil 15 is in a non-energized state (see FIG. 8; step S17). At this time, the control signal to the gate terminal of the n-channel FET 14b is activated to turn on the n-channel FET 14b. At this time, the gate terminal of the n-channel FET 14b rises with a delay time (γsec) determined by the time constant of the resistor R13 and the capacitor C12.

  Thereafter, the operations from step S12 to step S17 are repeated.

  In step S11, step S12, step S14, step S15 and step S17, when the predetermined angles (α °) and (β °) are equal to or smaller than the predetermined value, that is, the magnet rotor facing the central axis of the stator cores 19a and 19b. Even when the motor coil 15 is energized when the surface magnetic flux density of 20 is near the peak value, the repulsive force acting between the magnet rotor 20 and the stator cores 19a and 19b works toward the center of the motor rotation axis. The motor torque is not output.

  Further, since the amount of change in the magnetic flux of the magnet rotor 20 across the front of the stator cores 19a and 19b is small, the voltage induced in the motor coil 15 is also small, and the apparent voltage value applied to the motor coil 15 is large. A large current flows through the motor coil 15. Since this current does not contribute to the motor torque, all of it is wasted electric power, causing the efficiency of the single-phase DC brushless motor to be reduced.

  In the driving device for the single-phase DC brushless motor of this embodiment, as shown in FIG. 7, in steps S11, S12, S14, S15 and S17, predetermined angles (α °) and (β °) and The efficiency of the single-phase DC brushless motor is increased by controlling the energization / non-energization state of the motor coil 15 by providing a delay time (γsec).

  Here, the predetermined angles (α °) and (β °) are angles at which the absolute value of the gradient of the surface magnetic flux density of the magnet rotor 20 is equal to or less than “surface magnetic flux maximum value × SIN (45 deg)”. In the case of a single-phase DC brushless motor of (M is a positive integer), it is “45 / (M / 2) deg” or less. More preferably, the angle is such that “surface magnetic flux maximum value × SIN (15 deg) <inclination absolute value <surface magnetic flux maximum value × SIN (36 deg)”, and if it is an M pole single-phase DC brushless motor, “15 / (M / 2) deg <α, βdeg <36 / (M / 2) deg ”or less.

  The delay time (γsec) is the time for which the magnet rotor 20 rotates by (α + β) deg. For example, if the single-phase DC brushless motor is rotating n times [1 / min], “(α + β) / ( 360 × (n / 60)) sec ”.

  As described above, in the driving device for the single-phase DC brushless motor according to the present embodiment, the magnet rotor 20 having a plurality of magnetic poles and rotatably supported, and the stator cores 19a and 19b disposed to face the magnet rotor 20 are provided. A single-phase DC brushless motor driving a single-phase DC brushless motor having a motor coil 15 held by the stator cores 19a and 19b, and detecting an off-magnetic pole position for detecting the magnetic pole position of the magnet rotor 20. The switching elements 13a, 13b, 14a and 14b are turned on based on the magnetic pole position detection signal output from the sensor 16b, the switching elements 13a, 13b, 14a and 14b connected to the motor coil 15 and the off magnetic pole position detection sensor 16b. Alternatively, the motor coil 15 is energized by turning off or And when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 20 facing the stator cores 19a and 19b is within a predetermined range, the control circuit 17 turns the motor coil 15 on. The power is not turned on.

  Thus, when the absolute value of the rate of change of the surface magnetic flux density of the magnet rotor 20 facing the stator cores 19a and 19b is within a predetermined range, the motor coil 15 is controlled so as not to be energized. It is possible to improve the efficiency of the single-phase DC brushless motor, and avoid the situation of heat generation of the motor coil 15 and the control board or increase of power consumption as in the past. As a result, a single-phase DC brushless motor driving apparatus that can improve the efficiency of the single-phase DC brushless motor with a simple circuit configuration can be realized.

  In the driving device for the single-phase DC brushless motor of the present embodiment, the switching element after a predetermined time (delay time: γsec) has elapsed after the control circuit 17 outputs the magnetic pole position detection signal from the off magnetic pole position detection sensor 16b. Since the on / off control of 14a and 14b is performed, a single-phase DC brushless motor driving device that can improve the efficiency of the single-phase DC brushless motor at a desired rotational speed can be realized.

[Modification]
In the first embodiment and the second embodiment described above, the single-phase DC brushless motor is an H-bridge type single-phase full-wave DC brushless motor. A drive device for a single-phase DC brushless motor capable of driving a single-phase half-wave DC brushless motor with high efficiency with a simple circuit configuration as in the embodiment by controlling energization of the motor coil in accordance with the rate of change of magnetic flux density Can be realized.

  In the embodiment, the FET is used as the switching element. However, a single-phase DC brushless motor driving apparatus can be realized with a simple circuit configuration even when the bipolar transistor is used.

  Further, as in the embodiment, the configuration in which the gate terminal of the p-channel type FET is not directly connected to the drain terminal of the opposing n-channel type FET, but the configuration in which the gate terminal is connected through a resistor or a diode, is similarly simple. A drive device for a single-phase DC brushless motor can be realized with a circuit configuration.

  Further, in the embodiment, the Hall IC is used as the magnetic pole position detection sensor, but a Hall element may be used.

  If the drive device for a single-phase DC brushless motor of the present invention described above is incorporated in a single-phase DC brushless motor, the degree of freedom in circuit design in the drive device for a single-phase DC brushless motor and the output of a device using the single-phase DC brushless motor The performance can be greatly enhanced.

  In particular, the single-phase DC brushless motor driving device of the present invention can be expected to be applied to motor control of various liquid supply devices used in, for example, fuel cells and heat pump devices.

It is a block diagram of the drive device of the single phase DC brushless motor which concerns on Example 1 of this invention. It is explanatory drawing explaining the time transition of the relative positional relationship of the main components in the single phase DC brushless motor of Example 1. FIG. It is a time chart explaining the relationship between the magnet core surface magnetic flux density of the single phase DC brushless motor of Example 1, and an energization timing. FIG. 6 is an explanatory diagram for explaining a magnetic pole position detected by an on-magnetic pole position detection sensor 6a and an off-magnetic pole position detection sensor 6b according to the first embodiment and an energization state of a motor coil 5. It is a block diagram of the drive device of the single phase DC brushless motor which concerns on Example 2 of this invention. It is explanatory drawing explaining the time transition of the relative positional relationship of the main components in the single phase DC brushless motor of Example 2. FIG. It is a time chart explaining the relationship between the magnet core surface magnetic flux density and energization timing of the single phase DC brushless motor of Example 2. It is explanatory drawing explaining the magnetic pole position which the OFF magnetic pole position detection sensor 16b of Example 2 detects, and the energization state of the motor coil 15. FIG.

Explanation of symbols

1,11 Motor drive power supply (positive potential)
2,12 Motor drive power supply (negative potential)
3a, 3b, 13a, 13b p-channel FET (switching element)
4a, 4b, 14a, 14b n-channel FET (switching element)
5, 15 Motor coil 6a, 16a On magnetic pole position detection sensor 6b, 16b Off magnetic pole position detection sensor 7, 17 Control circuit 8, 18 Control power supply 9a, 9b, 19a, 19b Stator core 10, 20 Magnet rotor 41 Start-up time instruction circuit 42 Lock detection circuit R1-R4, R11-R14 Resistor C11, C12 Capacitor

Claims (5)

A single phase driving a single phase DC brushless motor having a magnet rotor having a plurality of magnetic poles and rotatably supported, a stator core disposed opposite to the magnet rotor, and a motor coil held by the stator core A driving device for a DC brushless motor,
A magnetic pole position detection sensor for detecting a magnetic pole position of the magnet rotor;
A switching element connected to the motor coil;
Based on a magnetic pole position detection signal output from the magnetic pole position detection sensor, control means for turning on or off the switching element to energize or de-energize the motor coil,
The control means performs energization control so that the motor coil is not energized when the absolute value of the change rate of the surface magnetic flux density of the magnet rotor facing the stator core is within a predetermined range ;
The energization control is performed when the center of the S pole of the magnet rotor and the center axis of the stator core are not more than a predetermined angle, and when the center of the N pole of the magnet rotor and the center axis of the stator core are not more than an angle. When the motor coil is in a non-energized state, the center of the S pole of the magnet rotor and the center axis of the stator core are not less than a predetermined angle, and the center of the N pole of the magnet rotor and the center axis of the stator core are predetermined. When the angle is not less than the angle, the motor coil is energized, and the predetermined angle is an angle at which the absolute value of the gradient of the surface magnetic flux density of the magnet rotor is equal to or less than the surface magnetic flux maximum value × SIN (45 deg). single-phase DC brushless motor driving device, characterized in that. The magnetic pole position detection sensor is
An on-pole position detection sensor for detecting a position of the magnetic pole for starting energization of the motor coil;
An off magnetic pole position detection sensor for detecting a magnetic pole position at which energization of the motor coil is stopped;
The drive device for a single-phase DC brushless motor according to claim 1, wherein:   The control means controls the switching element to be turned on or off based on a magnetic pole position detection signal output from the off magnetic pole position detection sensor until a predetermined time has elapsed since the start of the single-phase DC brushless motor. The drive device for a single-phase DC brushless motor according to claim 2.   3. The control device according to claim 2, wherein when the single-phase DC brushless motor is locked, the switching element is turned on or off based on a magnetic pole position detection signal output from the off magnetic pole position detection sensor. 4. The drive device for a single-phase DC brushless motor according to claim 3.   2. The single-phase DC brushless motor according to claim 1, wherein the control unit controls the switching element to be turned on or off after a predetermined time has elapsed after the magnetic pole position detection signal is output from the magnetic pole position detection sensor. Drive device.

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